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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Posted on 25 March 2011 by dana1981

Energy consulting firm Ecofys produced a report detailing how we can meet nearly 100% of global energy needs with renewable sources by 2050. Approximately half of the goal is met through increased energy efficiency to first reduce energy demands, and the other half is achieved by switching to renewable energy sources for electricity production (Figure 1).

To achieve the goal of 100% renewable energy production, Ecofys forsees that global energy demand in 2050 will be 15% lower than in 2005, despite a growing population and continued economic development in countries like India and China. In their scenario:

"Industry uses more recycled and energy-efficient materials, buildings are constructed or upgraded to need minimal energy for heating and cooling, and there is a shift to more efficient forms of transport.

As far as possible, we use electrical energy rather than solid and liquid fuels. Wind, solar, biomass and hydropower are the main sources of electricity, with solar and geothermal sources, as well as heat pumps providing a large share of heat for buildings and industry. Because supplies of wind and solar power vary, “smart” electricity grids have been developed to store and deliver energy more efficiently. Bioenergy (liquid biofuels and solid biomass) is used as a last resort where other renewable energy sources are not viable."

To achieve the necessary renewable energy production, Ecofys envisions that solar energy supplies about half of our electricity, half of our building heating, and 15% of our industrial heat and fuel by 2050. This requires an average annual solar energy growth rate much lower than we're currently achieving – an encouraging finding.

The report notes that wind could meet one-quarter of the world’s electricity needs by 2050 if current growth rates continue, and sets that as its goal. Ecofys also envisions more than one-third of building heat coming from geothermal sources by 2050. If we double current geothermal electricity production growth rates, it can provide 4% of our total electricity needs by that date. Ocean power, through both waves and tides, accounts for about 1% of global electricity needs in 2050. Hydropower, which currently supplies 15% of global electricity, ultimately supplies 12% in the Ecofys scenario. As you can see in Figure 2, global renewable energy use ramps up gradually between now and 2050.

Figure 2: Energy use by source between 2000 and 2050

Burning biomass (such as plant and animal waste) will supply 60% of industrial fuels and heat, 13% of building heat, and 13% of electricity needs. Much of the proposed biomass use comes from plant residues from agriculture and food processing, sawdust and residues from forestry and wood processing, manure, and municipal waste. All of these renewable energy technologies currently exist, and it's just a matter of implementing them on a sufficiently large scale.

Ecofys also envisions using currently existing technology and expertise to "create buildings that require almost no conventional energy for heating or cooling, through airtight construction, heat pumps and sunlight. The Ecofys scenario foresees all new buildings achieving these standards by 2030." 2–3% of existing buildings will also need to be retrofitted per year to improve energy efficiency. Ecofys notes that Germany is already retrofitting buildings at this rate. Transportation must become more efficient, using more fuel efficient vehicles like electric cars, and increasing use of mass public transportation.

Accomplishing all of this will require a major effort, but Ecofys has a number of suggestions how we can start:

Introduce minimum efficiency standards worldwide for all products that consume energy, including buildings

Help developing countries pursue alternatives to inefficient biomass burning, such as such as improved biomass cooking stoves, solar cookers and small-scale biogas digesters

Substantial investment in public transportation

Make individuals, businesses, and communities more aware of their energy consumption, and encourage increased efficiency

Undoubtedly you're wondering how much this will all cost. Ecofys finds that we will need to divert up to 3% of global gross domestic product (GDP) to investments in materials and energy efficiency, renewable energy, and necessary infrastructure. However, we also save money in terms of reduced fossil fuel use.

The report finds that we can save nearly 4 trillion Euros ($5.7 trillion) per year by 2050 based on energy efficiency savings and reduced fuel costs, as compared to business-as-usual. The up-front investments are expensive, but savings will begin to exceed those costs by 2040, and even sooner if oil prices rise faster than expected, or if we factor in the costs of climate change and the impact of burning fossil fuels on public health. The plan will reduce energy-related greenhouse-gas emissions 80% below 1990 levels by 2050, which will give us a fighting chance to avoid the 2°C global warming "danger limit".

There's a saying, "where there's a will, there's a way". In this case we have a way to fully transition from fossil fuels to renewable energy by 2050. The question is, do we have the will?

Comments

Glen @ 100. Anyone counting on the northern tundra to save our collective bacon is *really* living in Cloud Cuckoo Land. Even after the permafrost melts, the soil will be massively nutrient deprived. Second, almost *all* our crops (certainly grain crops) have been bred for the last 8,000 years to thrive in areas with a proper 4 seasons with ample sunlight throughout the year. Trying to grow these grain crops in areas that don't see the sun for more than 3 months at a time are hardly going to be ideal.

Here is the last forecast of the International Energy Agency, the respectable "watchdog" of OECD, concerning the future of oil production (WEO 2010)

Note the 40 Mb/d "yet to be developed" or "yet to be found" (meaning that we actually don't know where the hell we could find them.

Could you please explain me the "to be "? if there is no problem in suppressing totally oil in 2050, WTF do we care about missing oil ? are the experts of IEA unaware of how easy it is to suppress oil ? and no - this is not the baseline BAU scenario, it's already a "new policy" scenario.

So I'd like to have your opinion. Who are the clowns here ? IEA ? or Ecofys ?

The reason we walked away from the mine at Wittenoom and everywhere else was - we didn't want it any more.

Asbestos still has its insulating properties and it does have some specialist applications. But we decided it was just too dangerous and we could find other ways to do the things that we had been using asbestos for until that point.

I fully expect that we'll reach that point with coal and oil. I'd prefer sooner than later.

102 Gilles
To explain "to be". "New Policy Scenarios" means something like that all G20 carry through their commitments to renewables, GHG reduction etc. not that everyone or, indeed, anyone puts in place the Ecofys proposals. "yet to be" means, given demand projects, prices, cost of exploitation and discovery. Given which, the IEA puts in place a projection of what would have to happen in terms of exploitation and discovery to keep up with demand... (again) assuming current commitments are carried through.

Sooo, Gilles, if you want to know
"So I'd like to have your opinion. Who are the clowns here ? IEA ? or Ecofys ? "
The answer must be to look in the mirror.

BTW : how do you explain that despite of a very broad interval of energy consumptions and energy intensities, Ecofys scenario is also very far from the all sample studied in the SRES?

does it mean that the SRES has simply forgotten the whole interval of possible scenarios between Ecofys and its own set ? which makes a lot of forgotten scenarios !!! again, where are the clowns ? Sorry for the mirror, but I wasn't personally involved in any of these works. I just try to understand the huge discrepancies between them.

Oh so, hang on Gilles, now you're telling us that oil consumption *will* increase over the next 25 years? Weren't you saying just a few posts back that there was insufficient oil & coal to achieve the doubling of CO2 scenario? Are you really that inconsistent in your rants, Gilles, or do you genuinely suffer from an MPS?

106- Gilles
I think the point about the IPCC/SRES and the IEA that you are missing is that such bodies are not innovative research units. Their job is to take material coming out from research or government and combine such material to study outcomes. Such bodies loose credibility when they introduce stuff that is outside their brief.... they are, really, civil servants with commitments to transparency etc. - it's not like the blogosphere where people are free to bring in 'facts' from where ever they like to try to direct the argument in which ever direction they like.

And you're also saying that projections of fossil fuels reserves are made by civil servants who just take the material coming out from governments and combine them without any critical assessment - right, too ?

"Oh so, hang on Gilles, now you're telling us that oil consumption *will* increase over the next 25 years? "
I missed this one : Marcus,I'm not saying that - note the "yet to be found" : I just remark that IEA estimates that we need them - seeming to ignore that it is so easy to maintain our way of life without them. I doubt very much that we'll actually find them.

Gilles #112: "projections of fossil fuels reserves are made by civil servants who just take the material coming out from governments and combine them without any critical assessment"

For someone in love with discussing fossil fuel use, you don't seem to be very familiar with standard industry terminology and methods. Oil companies report their reserves in the categories of Proved Developed (PD), Proved Undeveloped (PUD) and Probable. Proved reserves (overall) are the volumes expected to be produced to a 90% confidence. PD are reserves currently under production; PUD is somewhat more speculative than PD, as these reserves are within a field's limits, but have yet to be placed on production. PUD and Probable (50% confidence) are most likely the 2nd gray-blue category on the graph you linked.

'Reserves to be found' is subject to exploratory risk. This is, at best, a statistical assessment (aka guess) based on historic results. Depending on circumstances, one can put anywhere from a 10-30% certainty on these numbers; I cannot say from the graph whether that factor is already applied.

There are not necessarily any 'civil servants' in this process; nor is there much of any 'critical assessment.' It is often an exercise is hyping a company's stock price or valuation to a potential buyer. There are internal goals to be met: the most common being replacement of a company's produced reserves with new discoveries each year; when a string of dry holes precludes that, 'creative' booking of more PUD reserves can cover the shortfall (I've been there and done that). Management bonuses are often dependent on these numbers; you can well imagine considerable conflict of interest arises from time to time.

In short, I see the graph you presented as a slightly optimistic BAU for oil and NGLs; 'unconventional oil' (presumably from enhanced recovery technologies) may be the 'new policy.' In that regard, projected increases in atmospheric CO2 under BAU are highly likely.

Please don't put words in my mouth - particularly about something I'm trying to explain to you to help you understand how the world works. It is both rude and won't help you either.

It's very clear, for example for the IPCC. Their brief is to do a report comparing all existing material. I'm not sure that they used all possibilities .... will, despite what some people think, the IPCC is populated by mortals who only have access to what's known. It's also seems to me that this is the same for the IEA report...

Now, go back and read what I wrote. e.g. "research or government" ... you quote me as "from governments". That is extremely rude, shows clear signs of bias and does you no credit at all.

les : what is wrong in 111 ? do the set of SRES scenarios encompass all likely possibilities for the future, or not ? I mean of course it would be much unlikely that a particular scenario corresponds exactly to reality : but you could expect that it will be inside the whole set, so let's formulate like this : what is the likelihood that the real history of production of FF in the XXIth lies outside the convex polyhedra built by the set of all SRES scenario for all (oil, gas, coal) production numbers, in order of magnitude ? 50 % ? 10 % ? 1 % ? less ?

114 Mucounter : I don't want to discuss here the plausibility of IEA scenarios - I just wanted to notice that they consider that oil is needed - notwithstanding the well known fact that we could so easily replace it, like all FF - isn't it somewhat strange that they seem to ignore such an obvious possibility ?

Cant help noticing Gilles claims that SRES scenarios make no account of resource restriction, seem somewhat at odds with SRES itself.

However, leaving that aside, suppose we drop all oil use now, dont replace oil with coal-created electric, so we only use half the coal by 2100, what the guess on CO2 ppm by 2050? Gilles doesnt believe in models so I doubt he cares, but frankly I still dont want to go there in less than 40 years.

Gilles#116: "I just wanted to notice that they consider that oil is needed - notwithstanding the well known fact that we could so easily replace it,"

Classic. You posted a graph (which you didn't cite until 9 comments later - perhaps because you clipped the graph from 'Republicans for Environmental Protection,' whatever that is), without explanatory reference to the report to which the graph belongs. You interpret the graph's 'oil to be found' to suit your biased needs. And reach a completely incorrect conclusion.

Here's the actual source document for the graph, which is indeed part of the IEA World Energy Outlook for 2010. Let's do what you conspicuously did not: Define the 'New Policy Scenario,' which you see as a statement that these 'clowns' consider that 'oil is needed.' From the factsheet:

In the New Policies Scenario ... world primary energy demand increases by 36% between 2008 and 2035, or 1.2% per year on average. This compares with 2% per year over the previous 27-year period. The scenario assumes cautious implementation of the policy commitments and plans announced by countries around the world, including the national pledges to reduce greenhouse-gas emissions and plans to phase out fossil-fuel subsidies.

So this is really a very limited attempt to reduce CO2 emissions; it is, by design, not a radical shift away from oil consumption. Later in the document, the New Policy Scenario is compared to the commitments of Copenhagen:

Were those commitments to be implemented in a cautious manner, as assumed in the New Policies Scenario, rising demand for fossil fuels would continue to drive up energy‑related CO2 emissions, making it all but impossible to achieve the 2°C goal. ...

Emissions jump to over 35 Gigatonne (Gt) in 2035 — 21% up on the 2008 level of 29Gt. Non‑OECD countries account for all of the increase; OECD emissions peak before 2015 and then begin to fall. These trends are in line with stabilising the concentration of greenhouse gases (GHG) at over 650 parts per million (ppm) of CO2‑equivalent, resulting in a likely temperature rise of more than 3.5°C in the long term. --emphasis added

So: The IEA doesn't consider that oil is needed, as you claim. They show a scenario of baby steps, in which oil use increases and we arrive at 650ppm and the high side of +3.5C. That's not a good outcome.

Really, Gilles, you've got to try harder. You've not yet shown that you have any inclination to do that; but at the very least, find out what you're talking about before forming an opinion.

scaddendp : what's your guess for the average slope of the temperature increase in the 4 next decades? I you predict an acceleration, It would be interesting to see how soon it will be measurable.

Mucounter 118 : what is classic is your continuous misreading of what I'm saying. First I didn't care about the website hosting this graph, I know it perfectly well and I already commented it a number of times since it appeared in fall 2010 in WEO 2010. I just was too lazy to find if it were published on line on the IEA site on a html page instead of the pdf I gave you in link - so I just googled "iea oil production WEO 2010" and I took the first occurence I found (the fact that guys like you are not aware of this kind of predictions is for me totally indicative of the total unawareness of the real problems of the coming decades, BTW).

You say it is only a "very limited attempt to reduce CO2 emissions". Thank you, I can read numbers. I know that. It wasn't my question. My question was : why does the IEA think oil is "needed", even the poor 20 Mb/d "yet to be found" if it is so easy to suppress it ?

I hope you don't think this graph has been obtained simply by adding commitments of all countries US+SFU+China+france+ Etc... No country can know exactly what its growth and energy consumption will be in 2030, and if you consider all the oil excluding NGL and unconventional, you can notice it is strictly flat. I hope you will agree that the likelihood that the sum of all commitments of all countries in the world is strictly flat for 30 years is extremely tiny. So is the likelihood that we would find exactly this amount. Obviously IEA has no way to know exactly how much oil will be found in yet unknown fields.

So think a little bit more about all this : on which basis can IEA produce such a graph ? any idea? may be les, who understands perfectly "how the world works" , could help you ?

Beg to differ; I have not misread you at all; you've set a pattern of saying X and claiming you said Y when you are called on it.

"My question was : why does the IEA think oil is "needed""

That was exactly what I addressed in #118, in particular where I demonstrated that your interpretation of the purpose of this graphic is utterly incorrect. Where do you obtain the idea that IEA thinks this scenario means that 'oil is needed'? It is merely a projection of what is likely to occur given the meager commitments made to reduce CO2 emissions. Interestingly, you've managed to steer the discussion away from what should be the main point: Given this likely scenario, we are headed for 650ppm! Maybe that is your real intention in being so persistent here.

"on which basis can IEA produce such a graph ?"

Easily. There are known production rates which are not going to accelerate radically in the near term. There is a finding rate based on historic industry performance, which can be used to forecast future production. Unless you believe the last barrel of oil has already been located, that is likely to continue in the near term. How do you think any industry makes projections for long term investment? It takes years to get a new product to market; it takes years to get newly discovered oil to market. Industry must make projections of future demand to justify investment.

You seem to believe that a scenario must either be absolutely true or else its worthless. This opinion is unfounded, yet all too common; indeed, the same ideas were stated by another commenter on a thread regarding computer modeling. Such statements indicate a profound lack of understanding. If you disagree with the results of a scenario or a projection, state your objection and back it up with specifics. Taking the attitude that 'all projections are subject to error and therefore worthless' is the lazy way out; you won't get away with it here.

"what's your guess for the average slope of the temperature increase in the 4 next decades? I you predict an acceleration, "

I predict that temperature curve will follow closely the model ensemble trend calculated for the scenario of CO2 emissions that we actually get. I dont predict what the emissions will be because that means guessing to what extent governments will move to limit them, as well as society response to resource constraint when they appear.

I also find the risks associated with BAU and high emission scenarios unacceptable.

Are you going to answer my question or just try another debating gambit?

Gilles#119: "you predict an acceleration, It would be interesting to see how soon it will be measurable."

Already happening. Maybe you're not paying close enough attention.

The red dots are the global LOTI temperature anomaly, shifted to 0 in 1880. The curves are deltaT = lambda dF, for 3 values of sensitivity. The small number below each curve is the equivalent sensitivity = deg C/double CO2; although these curves are a bit dated.

I'll go with the IPCC until about 2040. I will die during the 40s (if I've made it that far) so I won't see it, but I expect a fair bit of methane /clathrate release starting in the 30s. (Presuming we haven't got our CO2 release and sequestration act together by that point.)

so if we burn 400 Gt of coal, and may be 150 Gt of oil and 150 Gt of gas, we will burn approximately 700 Gt of C, giving 2 000 Gt of CO2. Given that the current production of 10 GtC/yr produce approximately +2 ppm/yr, this will eventually increase the CO2 concentration up to 540 ppm - you can do more sophisticated absorption models but that's the right order of magnitude.

If we assume that it would be very difficult to keep the total concentration below 450 ppm, the difference between 540 and 450 ppm is S * ln(540/450)/ln(2) = 0.3 S where S is the sensitivity - actually that holds for the equilibrium temperature and not transient response. Note that if the production is decreasing, absorption will become larger than production and after some time, CO2 will also decrease (Bern absorption model predicts only 20 % CO2 staying permanently in the atmosphere). So taking into account this uncertainties, I would say that if we burn 400 Gt of coal, the difference with the best scenario and this one would be around 0.5 °C in 2100, plus or minus the usual uncertainty.

it's not a new kind of maths : you just mixed up GtC (of carbon) (actually I should have written Gtoe) and GtCO2 (of carbon dioxide). There is a factor three between them 14 g CH2 -> 44 g CO2. You may be surprised by the result, but it is just due to the forgotten fact that most SRES scenario assume much more than the proved reserves for at least one of the FF - sticking to proved reserves doesn't produce that much CO2.

Gilles - CBD is doing no such thing, he is using YOUR figure 2000Gt of CO2, but noting the proven reserves give you enough CO2 for 790, not 540.

But even 540 is takes us to levels of Pliocene and older in the blink of the geological eye. You might feel safe about that but I certainly dont. And that assumes that rate of CO2 production stays constant at todays level (the conservative SRES scenario) despite increasing population and affluence. Hmm. I would frankly be very happy to if we managed to hold CO2 increase. What are you expecting to replace oil for transport as petrol dwindles? I'm guessing increasing electric and if we are not careful that will be produced from coal.

"most SRES scenario assume much more than the proved reserves"
Show me where? The ZJ values seemed to fit pretty well with the coal reserves.

Also, as someone who spent first 15 years of working life in coal resource estimation, I would say "proven" coal IS a conservative estimate. When you have a lot of proven reserve, there is little incentive to spend exploration dollars lifting the inferred reserves into proven, especially when costs of exploration are decreasing.

Excellent. The same Gilles who scoffed at 650ppm under an IEA oil forecast now reveals back-of-the-envelope numbers that take us well past even that horrifying level. But no worries, Gilles says it's OK because he can twist a near-doubling of CO2 (from pre-industrial) into only another 0.5C.

We've already seen +0.5C just since 1970, when CO2 was 325ppm; now its 390, a 20% increase. Gilles predicts: going to 540ppm, another 40% higher than today will result in just another 0.5C. Anyone (except Gilles) can see that's fuzzy math.

If you're doing back-of-the-envelope calculations, don't forget the methane from clathrates & permafrost... from memory, the permafrost component alone is supposed to add another 1,500 Gt of carbon all by itself - but in the form of methane, which is ~77 times worse than CO2 over 20 years, and 25 times worse over a century.

Add that to the 2,000 Gt of CO2 from humans, plus methane from clathrates, plus increasing temperatures turning sinks like rainforests & the oceans into net sources (and releasing significant amounts of the previously-absorbed human emissions) and we could be looking at some serious increases in greenhouse forcing.

Having just read the last 70-odd posts on this thread, it is clear that Gilles is arguing for continued use of fossil fuels, primarily because we don't currently price the externalities, and as a result it's currently the cheapest source of energy.

Actually, I'd go further, to say it sounds more like what you'd hear from an accountant, rather than an economist.

Given Gilles' persistence in posting here, and the content of the messages, I feel we're seeing one of two things: a sock-puppet, or someone who really believes what they're posting, a la this XKCD comic. Personally, I hope it's the latter. :-)

CBD has obviously confused CO2 and toe or C when he wrote
2,000 Gt CO2 / 10 Gt/yr = 200 years

since we produce around 30 GtCO2 and not 10 (this is the energy consumption).

everybody can do mistakes, but it is extraordinary that it requires an explanation PLUS another justification for people claiming I'm not acting like a scientist.

Mucounter : there is no mistake, I said 0.5 °C with respect to the the lowest reasonable value expected in 2100, not with respect to now. Please read me more carefully.

The problem in saying "the threshold of 2°C is dangerous and we must keep below it" is that even then natural variability of a few tenths of degrees corresponds to dozens of Gt of C, if not hundreds ; so you cannot define with precision the moment when you're supposed to stop. In the Ecofys scenario, they just offer a possible (probably unrealistic) future production, but they are totally silent about how insuring it for sure in the future : who will tell whom that it's enough and that he should stop now using FF ? this is just the product of sim-city formatted brains who believe the world is in their computers (I'm afraid many climate scientists suffer from this disease) . The peak in FF production is always governed by the offer, not the demand. No company stop drilling and extracting oil when the well is drilled, before it is exhausted. The only fact that will limit the extraction (and is acting just now for the oil) , is just that the resource becomes so expensive that the number of customers decreases : you're just seeing it's happening, but you don't seem to understand it.

"
Given Gilles' persistence in posting here, and the content of the messages, I feel we're seeing one of two things: a sock-puppet, or someone who really believes what they're posting, a la this XKCD comic. Personally, I hope it's the latter. :-)"

just a question for moderation : does this belong to the class of "ad hominem comments" , or not ?

Gilles, actually the '10 Gt/yr' value was yours too. Like I said, I didn't check your numbers... just pointed out that the math doesn't work. At that, if we change 10 to 30 it still doesn't come out to 540 ppm.

You don't give the calculations for how you get to 540 ppm only causing a 0.5 C increase over 450 ppm, but >my< 'back of the envelope' calcs would go something like this;

At best estimates of climate sensitivity a doubling of CO2 is expected to cause 3C warming from fast feedbacks (FF) and 6C warming from slow feedbacks (SF). Ergo;

FF * ln(2) = 3 -> FF = 4.33
SF * ln(2) = 6 -> SF = 8.66

ln(540/450) * FF = 0.79 C
ln(540/450) * SF = 1.58 C

So again, your 'abbreviated math' doesn't seem to match up. I was actually able to 'follow' your conclusion that 700 * 3 = 2000, but from there it seems to get progressively less accurate.

For the record, the 450 ppm figure was derived based on a goal of limiting fast feedback warming to 2C over the pre-industrial level. We can use this to validate my formulas above;

ln(450/280) * FF = 2.05C

Your '540 ppm is safe' view would instead put us at about 2.8C over pre-industrial levels... which most projections indicate would cause changes in sea level, freshwater supplies, and cultivatable land at a pace many nations would not be able to handle.

If you ignore the amount of carbon we're burning each year, I think you'd better refresh somewhat your readings. Actually it is a little bit less than 10 with FF only, a bit more including deforestation, but i'm only doing back-of-the-envelope calculations.
2000Gt/30 = 67 years approximately (not 200), giving 133 ppm more at the current rate, so it's more 520 ppm - I took 540 for a conservative estimate including methane, deforestation, and so on - CO2 is always the main driver.

I don't expect runaway methane emissions with such a level- please correct me if you know a valid reference that says the opposite.

Now I took only the transient response in 2100 , that's why I didn't take the full 0.8 °C - 0.5 °C is an order of magnitude. For slow feedbacks, you have to take into account that the CO2 will also decrease with time with the slow reabsorption by the wells after the production has decreased - the whole temperature curve must be numerically integrated but I don't expect it will vary much after that.

and as everybody knows, in 2100, we'll have found a lot of solutions to compensate for the loss of FF - which means in theory no limit for developing the whole mankind since finite stock resources won't be a problem anymore. I don't see why, if all mankind has become rich , it couldn't mitigate the impact of CC just as rich countries can do it currently.

Your '540 ppm is safe' view would instead put us at about 2.8C over pre-industrial levels... which most projections indicate would cause changes in sea level, freshwater supplies, and cultivatable land at a pace many nations would not be able to handle"

could you please find me a reference showing that any of these things would be manageable with 2 °C and not with 2.8 °C ?

is the 2°C some magic limit - it's fortunate that the Celsius scale gives suche an easily rememberable figure !

Bern, you deviate to other topics - I would like however to make you notice that "X and Y published dire predictions for Z centuries" is not per se a proof they're right.

And even if it were true, saying that doesn't say nothing about the inverse consequences of suppressing totally the FF consumption of the very same people you are supposed to save. You can claim that the consequences are negligible, but I stick to my question : if it's true, why does all energy agencies seem to ignore it ?

Gilles#135: "The peak in FF production is always governed by the offer, not the demand. No company stop drilling and extracting oil when the well is drilled, before it is exhausted."

You've already demonstrated that you know nothing about the oil business; at least you're consistent because that's just false. Wells are abandoned when the economics turn unfavorable. If it costs more to produce than you can get for it, you stop producing.

Why do you assume it is the business of an 'energy agency' to do anything other than what they are instructed to do? In these cases, you've created some mythic significance from the presence of an 'oil to be found' term in an IEA forecast, fabricating a conclusion from it: 'They include it, so it must be vital to our society.' Nonsense.

And now come the back-of-the-envelope calculations, which are of course based on complete understanding of energy use. This is the more appropriate xkcd for this situation.

Now if you think that the decrease of oil production will be driven by lower demand and reconversion to other energy sources, and not by geological availability, there is a very simple associated prediction : that prices should plunge and oil extraction will be given up because there aren't enough customers - that exactly what happened in the 80's with the oil counter-shock, that provoked both a nosedive of barrel price and a decrease of production/consumption - and this happened also very briefly just after the 2008 recession .

But if the decrease is due to a lack or resources, you expect just the opposite : that the price will climb to heaven and that the high price will discourage customers to buy it -much probably through strong recessions and demand destruction.

what's your favorite scenario ?

concerning agencies : too bad that all sres scenarios are based on the numbers provided or used by the same agencies. But I don't see why they would be "instructed" to say that we need to find new oil fields that we don't know yet where they are- that's not good news for OECD !

Gilles#143: "decrease of oil production will be driven by lower demand and reconversion to other energy sources, and not by geological availability"

Oil production is driven in part by all those factors, but it is primarily driven by economics. Once the initial investment is made, the time value of money demands a targeted production schedule. Depletion inhibits production, so we often do not meet those targets.

"exactly what happened in the 80's with the oil counter-shock, that provoked both a nosedive of barrel price"

You can believe in shock/counter-shock models if you like. But we must have lived through different decades: the oil price drop of the mid-80's was a means of destabilizing the Soviet Union. Why else would half a million US jobs be sacrificed with hardly any notice outside the oil patch?

"I'm saying nothing else for oil." That will help you from digging any deeper holes in what remains of your credibility.

"I don't see why they would be "instructed" to say that we need to find new oil fields that we don't know yet where they are-"

Borderline gibberish. We know where to find oil -- in oil-producing basins. The industry will not suddenly stop finding oil this year or in the next decade; the projection of 'oil yet to be found' expresses that confidence. It will simply become increasingly expensive to find and produce new oil - and that is what will inevitably make renewables economically attractive.

"what's wrong with back-of-the-envelope calculations ?"

They are usually incorrect. Yours are tantamount to "racecar on a train."

Mucounter : I don't see clearly your point - I agree with most of what you say, but what do you try to prove against what I'm saying ? and why would it contradict the "back-of-the-envelope calculations" ?

Gilles #146: "why would it contradict the "back-of-the-envelope calculations"?"

Do you really need me to point out the difference between your 'let's assume we burn X Gtons of coal, Y oil and Z gas' and calculations based on real data and more informed projections? Or do you place your X, Y and Z guesstimates in such high esteem that we should accept them and throw over peer-reviewed science in toto? If so, please furnish your address, so that we may make pilgrimage to visit such an all-seeing oracle. Check that, just give me the name of the winning horse in the 9th at Aqueduct tomorrow; I'll give you a cut.

Really. Science is not based on 'I disagree, so I get to make up my own numbers.' If you think it is, then you are indeed proposing a racecar on a train as a counter-example of special relativity.

148 : I was just answering question asked by scaddenp #117 and #121 so please don't reproach me it now !

and which "more informed" information? are you serious ? where is the bettest information used by the SRES, since oil and coal production are free to vary randomly between almost zero and tens of Gt at the end of century ? I said it already, a child with a set of colored pencils would have produced exactly the same set of curves - no information there, just "what if" scenarios (and I can give you references showing that even climate scientists recognize that if you insist).
I just used the official proven reserves, I did not invent them. The simple fact is that SRES scenarios do simply not care about proved reserves - they just take all kind of proved, unproved, potential, unconventional resources as if we could extract them at the same pace as conventional ones - which is an economical heresy - and peak oil is just currently demonstrating how ridiculous it is. You're just confident in people who repeatedly failed in forecasting energy crisis, that is just now upon us. We begin the era of struggle for exhausting resources - meaning in reality the end of economic growth - and people will desperately fight to keep as much as possible their standard of living while constantly receding. And the outside temperature will just be their least concern, when looking at their energy bill or learning they have just been fired.

"people will desperately fight to keep as much as possible their standard of living while constantly receding. And the outside temperature will just be their least concern, when looking at their energy bill or learning they have just been fired."

And to think that I have been called an alarmist on this very site, without ever producing anything near that kind of a panic in words.

Well Gilles, it sounds like you're advocating the complete eradication of fossil fuel use on an industrial scale before it imposes itself on us. Sounds wise. Seems that you're suggesting that the effort should be started as soon as possible in order to maximize the chances to ease up what will be anything but easy. Many will likely agree with you on that.